Replace the control of a flying saw cutter machine

You touched on a lot of excellent points.  If you were able to  do 1mm, then you did very well.

The simples and most problematic component is the measuring wheel.  We tried many positions and found the most stable to be not close to the saw, but in between the last forming stand and the undriven straightening stands.  Since no elongation happens in the straightening stands, the length is unchanged.  The encoder signal is also very noisy.

The extrapolation time correction is crucial to accuracy.

The carriage torque must be reduced while the product is clamped (ideally neither pushing or pulling).  I set it for slight pull to compensate for eventual wear on the guides.

We routinely do 120m/min and I've tested at 150 and accelerations as high as 1.2G.  Most of our saws are for smaller products, so we use belt drive to reduce the carriage mass. 

Jeff,

I got mad to commissioning the machine. I spent double time compared with the forecast at the time I made offer to the OEM, and this because of lack of experience (mine and also the OEM my customer)!

The accuracy +/- 1mm rise up to +/-5 mm as soon as the encoder position is wrong or the main drive torque is too much or the encoder vibrate or the pipe flex between the last roller and the flying shear .......

pigroplc

Or the encoder slips, or any one a one hundred other problems.

Flying cut machines are always a blood bath.  Unfortunately, we build them and I have to make them work.

Flying cut machines are always a blood bath.

 great sentence!

pigroplc

New question published by KIP_man is split to a separate thread with the subject Flying saw accuracy problem

Best regards
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